Composite gas-liquid pressurizing engine



` COMPOSITE GAS-LIQUID PRESSURIZING ENGINE HIROSHI SUGIMURA ATTORNEY June 4, 1968 HlRosHl suGlMuRA l 3,386,246

COMPOSITE GAS-LIQUID PRESSURIZING ENGINE Filed Feb. 25, 1966 2 Sheets-Sheet 2 vlsf-.2. 1

INVENTOR HIROSHI lSUGIMURA ATTORNEY United States Patent Olce 3,385,246 Patented June 4, 1968 3,386,246 COMPOSITE GAS-LIQUID PRESSURlZlNG ENGINE Hiroshi Sugimnra, 156 2-chome, Higashitamachi, Suginami-lru, Tokyo, Japan Filed Feb. 25, 1966, Ser. No. 530,161 19 Claims. (Cl. Gli-221) ABSTRACT F THE DISCLGSURE The invention comprises an engine with a built in pump having a liquid intake and a separate gas intake such as for water and air, respectively. The pump combines the liquid and gas under pressure and it discharges them t0- gether into a gas-liquid separator. The separator, which may be of the centrifugal type or of the gravity type, has a liquid outlet connected to a jet nozzle for performing useful work. The separator also has a gas outlet which is connected to the inlet of a gas turbine through gas expansion means. The drive shaft of the turbine is driveably connected to the pump or pumps and optionally to the separator. A detector may be associated with the liquid level of the separator to control a valve in the gas intake of the pump. Several variations include recycling liquid from the jet to the pump intake and recycling liquid from the outlet of the separator to its inlet.

The present invention relates in general to a composite gas-liquid pressurizing engine, and more particularly to a composite air-water pressurizing engine which is suitable for use in ships as a marine jet engine although it is not limited thereto.

In the past it had been proposed to replace the screw propeller for propelling a ship by the water jet in order to overcome various disadvantages of the former s-uch as, for example, increase of ship at a higher speed, difliculty in obtaining a high power, etc. However, the designs of the water jet engines contemplated in the prior art were common in that an independent engine is used for rotating various types of water pumps instead of rotating the screw propeller and that the water output of the water pump served as a water jet for propelling the ship. Therefore, in view of the power system, the above-described type of water jet in the prior art is equivalent to the colt nozzle screw which is a screw encompassed by a cylindrical casing, and it has an increased power loss at various parts and a higher fuel consumption.

In order to realize a truly useful and ei'licient water jet engine, it must be designed so that the engine itself can produce a pressurized water output which may be used as a water jet, without relying upon a mere aggregation of a conventional engine and a water pump. Furthermore, if the above-described type of water jet engine has been completed, obviously the use of the engine will not be limited to a water jet for propelling ships, but will be also applicable to any desired mechanical loads such as those requiring a rotating power.

In the above-referred type of water iet engine, there must be provided a liquid system for supplying a liquid output such as water jet, and a gas system for achieving the working cycle of a heat engine while receiving a power from fuel material. Here it has been proposed to pressurize the gas and the liquid together and then to separate them from each other for use in the gas and liquid systems respectively. This novel method of composite pressurizing results in advantages that thanks to the coexistence of the liquid the composite gas-liquid pressurizing pump can carry out a perfectly gas-tight compression without requiring any other lubricant which might be necessitated in a conventional gas compressor, and that the compression of the gas is carried out while being maintained at a temperature so low as possible and thus the eciency of the heat engine in the gas system may be enhanced.

Therefore, it is a principal object of the present invention to provide a novel composite gas-liquid pressurizing engine which can supply a liquid output at an enhanced eiciency.

According to one feature of the present invention there is provided a composite gas-liquid pressurizing engine comprising composite gas-liquid pump means for intaking gas and liquid separately and pressurizing them together, means for separating the pressurized gas and liquid fed from said composite gas-liquid pump means, and means for heating said pressurized and separated gas, wherein the energy possessed by said heated gas may be utilized by the intermediary of said separated liquid.

These and other features and advantages of the present invention will become apparent from perusal of the following specication taken in conjunction with the accompanying drawings, in which FIGS. la, 1b and lc show ilow diagrams with respect to gas, liquid and energy in the novel composite gasliquid pressurizing engine according to three representative embodiments of the present invention, respectively,

FIG. 1b is an explanatory table of symbols used in the drawings,

FIG. 2 shows a longitudinal cross-section view of one embodiment of the present invention,

FIG. 3 shows a schematic longitudinal cross-section view of another embodiment of the present invention,

FIG. 4 shows one example of the gas-to-liquid ratio regulating means to be incorporated in the embodiment of FIG. 2,

FIG. 5 shows another example of the gas-to-liquid ratio relating means to be incorporated in the embodiment of FG. 3, and

FIG. 6 shows a schematic longitudinal cross-section view of still another embodiment of the present invention.

Referring now to FIG. 1 of the drawings, three representative embodiments of the present invention are shown as FIGS. la, 1b and lc mainly for the purpose of illustrating the modes of ilows of gas, liquid and energy. In this figure, as indicated at the bottom a thin-inked solid line arrow represents the gas ilow, a heavy-inked solid line arrow represents the liquid flow, and a dash-dot line #arrow represents an energy flow. Also a thin-inked dotted line arrow represents the gas flow which may be optionally provided depending upon whether the engine is of open type or closed type with respect to the gas system. Similarly, a heavy-inked dotted line arrow represents the liquid ow which may be optionally provided depending upon whether the engine is of open type or closed type with respect to the liquid system.

More particularly, in the embodiment shown in FIG. la, at iirst the gas and liquidare intaken separately to cornposite gas-liquid pump means 1 such as, for instance, a conventional screw pump a conventional nash pump where they are pressurized together, the pressurized gas and liquid being fed to separating means 2 where they are separated from each other, and the pressurized and separated gas is heated to an elevated temperature in heating mean-s 3 such as, for instance, a heat exchange charnber and a fuel combustion chamber of a conventional gas turbine. The pressurized and heated gas gives its possessing energy to the above-mentioned composite gas-liquid pump means 1 for driving the same through any appropriate mechanisms such as a conventional gas turbine and a gear transmission system, and then the gas is exhausted to an outer atmosphere after it has susbtantially released its energy. In this case, the above-mentioned engine forms an open system with respect to the gas. On the other hand,

as shown by a thin-inked dotted line arrow in the figure, the gas exhausted from this engine may be optionally fed back to the gas intake of the composite gas-liquid pump means l. in this second case, the engine forms a closed system with respect to the gas. The pressurized and separated liquid from the separating means 2 serves as an output of this engine and gives its possessing energy to any desired load. According to one example of application of this type of engine, water is employed as the liquid and the engine output is realized as a water jet of a marine jet engine. Then the ship propelled by this marine jet engine is deemed to be the load with respect to the sea water. Accordingly, the closed system with respect to liquid as shown by a heavyinked dotted line cannot be realized. However, if the pressurized liquid serving as an engine output is used to generate a rotating power through a conventional hydraulic turbine, then the liquid may be, after releasing its possessing enero fed back to the liquid intake of the composite gas-liquid pump means 1 to complete a closed system with respect to the liquid. Thus it will be seen that the output of this type of engine may act upon the load either as a liquid jet or as a rotating power. Finally, reviewing this flow diagram in FIG. la

mainly with regard to the energy flow, it is apparent that the origin of the energy is the fuel combustion in the heating means 3, and that the eventual energy output is the pressurized liquid fed from the separating means 2.

Nextly in the second embodiment shown in FlG. 1b, the composite gas-liquid pump means ll, separating means 2 and heating means 3 and their mutual relation is exactly the same as those shown in FIG. la. The only difference exists in that the pressurized liquid separated by the separating means 2 is additionally pressurized through secondary pressurizing means -fi by the energy derived from the heated gas fed from the heating means 3, and then applied to the load as the engine output. The energy possessed by the heated gas is also applied to the composite gas-liquid pump means 1. These transmissions of energy from the heated gas to the composite pump means l as well as the secondary pressurizing means 4 may be realized by means of a conventional gas turbine and a gear transmission system.

Here it will be better to refer to the methods of separating the gas and liquid. One preferred method is that relying upon a centrifugal force, in which the mixed and pressurized gas and liquid are rotated in a casing by means of a rotor having suitable vanes, and the pressurized gas is derived from the center portion of the casing while -the pressurized liquid is derived from the peripherical portion of the separator casing. Another preferred method is that relying upon a difference in specific gravity between the gas and liquid in which the mixed and pressurized gas and liquid are guided to a bottom portion of the separator casing, then led upwardly through a vertical guide tube. The pressurized liquid reaches the highest level and then descends downwardly in the casing around the vertical giude tube, and finally derived from the liquid output port provided at the bottom and peripherical portion of the separator casing. On the other hand, the pressurized gas 1s released from the highest level, that is, from the free liquid surface, and derived from the gas output port provided at the top of the casing. In the first method, i.e., the centrifugal method, the structure of the separator is somewhat complexed since it includes ya rotor which must be driven at a high speed. However, this method is suitable for such case that the pressure of the liquid supplied from the separator is required to be higher than that of the gas which is supplied from the separator to the gas turbine, because as a nature of the centrifugal force the pressure of the gas localized at the center portion is lower than the pressure of the liquid which is shifted to the peripherical portion. On the contrary, in the second method, Le., the gravitational method, the structure of the separtor is rela tively simple and it does not require a driving power. However, according to this second method, the pressures of the separated gas and liquid are substantially equal to each other, and therefore, in some cases in which a higher liquid pressure is required by the load such as, for example, in the case of the marine water jet engine, the pressurized and separated liquid must be further pressurized by means of the energy supplied from the pressurized and heated gas before the liquid is yapplied to the load. Thus it will be easily seen that the embodiment shown in FIG. lb which incorporates the secondary pressurizing means 4, is often selected when the gravitational type of separator is employed.

in the third embodiment shown in FIG. 1c, the composiie gas-liquid pump means l, the separating means 2, and the heating means 3 and their mutual relation are also the same as those shown in FlGS. la and lb. In addtion, the secondary pressurizing means 4 just as provided in the second embodiment is also incorporated in this embodiment. However, the energy possessed by the heated gas supplied from the heating means 3 is solely used to additionally pressurize the separated liquid from the separating means 2, and it is not directly applied to the composite gas-liquid pump means l just as done in the first and second embodiments. Instead, the additionally pressurized liquid serving as an engine output acts not only upon the load but also upon the composite gasliquid pump means l for driving the same. Accordingly, in case that the engine output is used as a rotating power by means of a hydraulic turbine, it is only necessary to couple the driving shaft of the composite gas-liquid pump means 1 to the driven shaft of the hydraulic turbine. It is also the same as the embodiment shown in FIG. la that the liquid system and the gas system may be formed either in an open type or in a closed type in the embodiments of FIGS. lb and lc as indicated by the thin-inked and heavy-inked dotted line arrows.

Reviewing the above-described three modes of embodiment of the invention shown in FIGS. la, 1b and lc in general, although the methods of utilizing the energy possessed by the pressurized and heated gas are diiferent from each other, one may easily find out the essential feature of the present invention which is common to these three modes of embodiment, that is, the feature that the gas and liquid are pressurized together in the composite gas-liquid pump means 1 and then separated from each other by the separating means 2, and the pressurized and separated gas is heated by the heating means 3, and that the energy possessed by said heated gas is utilized by the intermediary of said separated liquid.

Thanks to the above-referred feature, the engine according to the present invention is very efficient in function and relatively simple in construction which results in the reduction of weight, space and cost in comparison with the prior art engine such as formed by merely aggregating a conventional gas turbine and a hydraulic pump driven by said gas turbine. This is because the compression of the gas for use in the gas turbine and the pressurizing of the liquid for use as an engine output are carried out simultaneously at a relatively low temperature in a very gas-tight manner by means of the composite gas-liquid pump, without requiring to provide both the gas pump for the gas turbine and the hydraulic pump for the liquid output. Here it is to be noted that although the additional pressurizing means 4 is used in the ernbodiments shown in FIGS. lb and lc, this additional pressurizing does not form an essential component of the general concept of the present invention, but it may be incorporated only when the load requires a higher liquid pressure than the pressure of the liquid at the liquid output of the separating means.

Now the three representative modes of embodiment of the invention described above, will be shown in a more detailed form with reference to FiGS. 2 to 6. Referring to FG. 2 of the drawings, a composite gas-liquid pressuriziug engine according to the present invention is shown which is practiced as a water jet engine for propelling a ship. Although the ship itself is not shown in this ligure, it is apparent that this marine Water jet engine is mounted on the ship at a level lower than the Water level indicated by WL in such manner that a top opening of an air intake tube 11 is positioned above the water level WL and a water intake 12 and a water jet nozzle 13 are positioned at appropriate levels beneath the water level WL. The water jet engine in FIG. 2 mainly consists of a composite gas-liquid pump 14 having the air intake 11 and the water intake 12, a frusto-conical type of centrifugal separator 15 having the water output 13, a conventional gas turbine 16, and a gear transmission system 17 for coupling a shaft 18 of the gas turbine 16 to a common shaft 19 of the composite pump 14 and the separator 15. The composite gas-liquid pump 14 is essentially a conventional high speed screw pump, which functions to intake air and Water separately from the respective intake devices 11 and 12, to mix and pressurize them together while a screw rotor 20 is being rotated by the gas turbine 16 through the shafts 18, 19 and the gear transmission system 17, and to feed the pressurized air and Water leftwardly into the centrifugal separator 15. The frusto-conical type of centrifugal separator 15 consists of a frusto-conical outer shell 21 which is xedly mounted and integrally coupled to an outer shell 22 of the high speed screw pulmp 14, and a frusto-conical rotor 23 which is coaxially and rotatably supported within the outer shell 21 by bearings 24 and 25 and has suitable form of blades for rotating the air and water held therein. In this gure, only the edges of the blades are shown at 26. The rotor 23 having the blades is integrally coupled with the driving shaft 19 as well as the pump screw 20, so that the rotor may be rotated at a high speed when the gas turbine 16 operates. Then the air and Water fed together from the high speed screw pump 14 and rotated within the rotor 23, are separated from each other owing to the centrifugal force acted upon during this rotation and the difference in specific gravity between the air and water. Thus the water occupies the peripherical region as indicated by W, while the air occupies the center region as indicated by A, the boundary surface Ibetween these two regions W, A being shown by a dotted line 27. The separated Water is derived from the peripherical portion of the end surface of the rotor having a larger diameter through an opening 28 of the outer shell 21 and the water output nozzle 13.

On the other hand, the separated air is derived from the center portion of the end surface of the rotor having a larger diameter through a guide pipe 29 to a heat exchange chamber of the gas turbine 16. The pressurized and separated gas is, after preheated in the heat exchange chamber by the remaining heat of the exhaust gas from the gas turbine 16, heated to an elevated temperature in the succeeding combustion chamber 31 by the combustion heat of the fuel supplied from a fuel nozzle 32. Then the heated gas serves to drive the gas turbine rotor coupled to the shaft 18, and after having released its possessing energy it is exhausted to an outer atmosphere through an exhaust tube 33, the heat exchanger 30 and an exhaust tube 34. The rotating power generated on the shaft 18 of the gas turbine 16 is converted to an appropriate angular velocity by means of a gear transmission system 17 and then transmitted to the driving shaft 19 which is common to the high speed screw pump 14 and the centrifugal separator 15. In order to clearly set forth the air system and the water system in the above-described composite air-liquid pressurizing engine, the flow of -air is indicated by thin-inked solid line arrows, and the iiow of water is shown by heavy-inked solid line arrows. In addition to the above-described components, the water jet engine in FIG. 2 comprises an apparatus for regulating the ratio of flowrate of the air to water, which consists of an adjusting valve 35 provided in the air intake tube 11 and a float 36 for detecting the position of the Water surface within the separator 15. The oat 36 is rotatable about its pivot 37, and its left-side end moves in accordance with the change of the water surface. Therefore, the change of water surface may be detected as an angular displacement of the oat 36. This angular displacement controls the position of the adjusting valve 35 through an appropriate mechanical linkage so that when the water surface in the separator is raised the adjusting valve 35 may -be further opened to permit more air being intaken to the composite pump 14. The more detailed structure of this regulating apparatus will be described later with reference to FIGS. 4 and 5.

From the above description, it will be easily seen that the water jet eng-ine illustrated in FIG. 2 corresponds to the embodiment shown in FIG. la in connection to the mode of utilizing the energy possessed by the heated gas. Also it will be seen that the separator employed in this example is of centrifugal type, and both the gas system and liquid system are of open end type.

With lreference t-o FIG. 3, there is shown another embodiment of the present invention which corresponds to the embodiment shown in FIG. lb in connection to the mode of utilization of energy, and in which a separator making use of the difference in specific gravity between the `air and water is employed. This embodiment is Valso practiced as a water jet engine, which comprises an air intake 38, a water intake 39, a composite air-water pump 40 essentially consisting of a high speed screw pump, a gravita-tional type of separator 41, a secondary water pump 42, a water jet nozzle 43, an air output tube 44 of the separator, a heat exchanger 45, a combus-tion chamber 46, a conventional gas turbine 47, an ex'haust 48 of the gas turbine, and a gear transmission system 49. The composite air-water pump 40 and the secondary water pump 42 are driven together by the gas turbine through the gear transmission system 49 and the bevel gear assembly 50 provided in the water intake region 39. The air and water intaken respectively through the air intake 38 and the water intake 39 are mixed and pressurized together b-y the high speed screw pump 40 and then fed to the separator 41. In the separator 41, the water and air go upwardly along a guide tube 51. After arrival at the highest level `52, the water goes downwardly outside the guide tube and Iis fed to the secondary water pump 42. As described before, in the case of the gravitational type of separator, the pressure of the water output and the gas output is substantially equal, and consequently the water pressure is not suicient to be used as a water jet. Therefore, the pressure of the separated water is increased by the secondary water pump 42 and then ejected through the water jet nozzle 43 for propelling the ship on which this marine jet engine is mounted.

On the other hand, the air admixed with the water is released at the highest level 52 of the water in the separator 52, and then guided upwardly through the gas output tube 44. After preheated in the heat exchanger 45, the air is heated to an elevated temperature in the comfbustion chamber 46 by means of the combustion heat of the fuel supplied through a fuel nozzle 53. The heated air serves to drive the gas turbine 47, and after releasing its possessing energy it is exhausted to an outer atmosphere through the heat exchanger 45 and the air exhaust tube 48. As mentioned at rst, thus generated rotating power is used to drive the composite pump 46 and the secondary pump 42. By reviewing the flow of air, water and energy in this example, it will become apparent that the water jet engine illustrated in FIG. 3 corresponds to the mode shown in FIG. lb. Though both the water jet engines in FIGS. 2 and 3 form open systems with respectV to both the air and the water, they may be arbitrarily modified to closed systems by feeding back the air exhaust to the air intake, or by driving a wate-r turbine by means of the water output and feeding back the water exhaust of the water turbine to the water intake of this engine. Of course, it must be kept in mind that when the engines shown in FIGS. 2 and 3 are modified to an open end type with respect to air, the combustion chamber asse 24e should be replaced by an indirect heating chain-ber which serves to heat the pressurized air Iby means of `an outside fuel burner. Since the cross-section view in FIG. 3 is depicted in a schematic manner, the air-to-water ratio regulating apparatus as described with reference to FIG. 2 is not shown in this figure. However, it is apparent that if it is necessitated to regulate the air-to-water ratio, the similar apparatus may be incorporated in the water jet engine shown in FIG. 3.

Now with reference to FIGS. 4 and 5 the detailed structure of the air-to-water ratio regulating apparatus will be described. Upon operation of the composite gasliquid pressurizing engine according to the present invention, if the liquid tlow is too much with respect to the gas flow, it may possibly occur that in the separator the liquid is splashed into the gas output tube and the spray of the liquid is mixed to the gas supplied to the combustion chamber. This apparently results in disadvantages in the operation of the engine. On the other hand, if the gas ow is too much with respect to the liquid ow, it may possibly occur that bubbles of the gas are admixed in the separated liquid. This results in the reduction of the liquid power output, Therefore, in the composite gasliquid pressurizing engine of the present invention it is desirable to incorporate an apparatus for regulating the ratio of ow rate of gas to liquid. FIG. 4 shows such regulatin y apparatus which is adapted to be incorporated in a centrifugal type of separator. This is an enlarged view of the regulating apparatus 35, 36 and 37 shown in FIG. 2. While, FIG. shows a regulating apparatus which is adapted to be incorporated in a gravitational type of separator such as shown in FIG. 3.

In FIG. 4 a choke valve 54 for adjusting the gas llow is provided in a gas intake tube 55 which corresponds to the gas intake l1, 38 in FIGS. 2 and 3 respectively. The valve 54 is rotatable around its pivot Se and rigidly coupled to an actuating lever 57. The valve S4 and the actuating lever 57 are subjected to a bias force on the anticlockwise direction by means of any suitable resilient means (not shown). Therefore, it no drag force is acted upon the lever 57 from the liquid level detecting device in the right hand side, the adjusting valve S4 takes the completely choked position as shown by the dotted line. This adjusting valve is shown in FIG. 2 at 3S and also in FIG. 3 by three slant lines in the gas intake 38 schema-tically. On the other hand a movable iioat 58 is supported at a pivot 59, and an actuating lever 66 is rigidly coupled to this movable oat 53. Between the extreme ends of the levers 57 and 60 is stretched a thin wire or string 61. The liquid level detecting device consisting of the iioat 5S and lever d() is schematically shown in FIG. 2 at 36, 37. It is assumed that the liquid level in the centrifugal separator such as shown in FIG. 2 will vary between the lowest level L1 and the highest level L2 depending upon the ratio of how rate of the gas to liquid. Obviously the movable oat S8 may swing between the two positions illustrated by the solid line and the dotted line respectively. When the liquid level tends to rise towards the level L2, the float 58 and the lever 60 rotates integrally in the clockwise direction and thus causes a clockwise rotation of the valve S4 and the lever 57 through the wire or string 61. Accordingly, more gas iiow is introduced through the gas intake tube 55 into the composite gas-liquid pump and the separator. Since the gas-to-liquid ratio is enhanced, the liquid level in the separator is suppressed to rise, and thus the predetermined position of the liquid level between Ll and L2 may be maintained. Quite similarly, when the liquid level tends to fall toward the level Ll, it is suppressed by slightly choking the gas flow in the gas intake 55, and thus the predetermined liquid level may be maintained. Consequently the ratio of flow rate of the gas to liquid may be maintained at a predetermined value during the operation oi this engine.

In FIG. 5, there is shown a gravitational type of separator provided with a liquid level detecting device. As

previously described, the mixed gas and liquid introduced into a separator chamber e?. through an inlet 63 and an upward guide tube d4, are separated in this chamber due to the difference in specic gravity between the gas and liquid and derived through a gas outlet 65 and a liquid outlet 66 respectively. A liquid detainer 62' is provided below Ithe outlet 65 whereby the separated gas in chamber 6 is permitted to hit the detainer and whereby the liquid splash involved therein falls to insure that air alone will pass through the gas outlet and prevent liquid from passing into the gas turbine. In order to supervise the ratio of iiow rate of the gas to liquid, that is, in order to detect the liquid level 67, there is provided a movable float 68 consisting of a oat head 69 which follows the liquid level 64 and an actuating lever '70 which is pivotably mounted at 7l. The extreme end of the lever 74B is connected to a thin wire or string 72 which leads to an actuating lever of an adjusting valve such as shown in FIG. 4. For the purpose of avoiding the motion of the movable oat due to waves generated along the liquid surface, a guard tube 73 surrounds the iloat head 69. From the above descrip- `tion of the structure, it will be easily seen that the liquid level detecting device 68, 69, 76, 71, 72, 73 in FIG. 5 functions quite similarly to the detecting device 58, 59, et) in FIG. 4, if the arrowed end of the wire or string 72 is connected to the actuating lever of the adjusting choke valve in the gas intake tube such as shown in FIG. 4. Thus the liquid level 67 in the separator chamber 62 may be maintained at a xed level for keeping a predetermined value ot the gas-to-liquid ratio.

In FIG. 6, there is shown another embodiment of the present invention which is equivalent to the mode shown in FIG. lc in connection to the method of utilizing the energy possessed by the heated gas. As in the case of FIG. lc, the flows of gas (air) and liquid (water) in this engine are shown by thin-inked solid line arrows and heavyinked solid line arrows, respectively. The part 74 is a conventional nash pump having a rotor 7S mounted on a common drive shaft 76, an air intake 77, a water intake 78, an air outlet 79 and a water outlet Si). This nash pump 74, functions to mix and pressurize the gas and liquid together and supply them separately through the respective outlets by making use of a centrifugal force. Therefore, the nash pump is deemed to be essentially a combination of a composite gas-liquid pump and a centrifugal separator. On the common drive shaft 76 are also mounted a cooling fan 8l for the water system and a water turbine 82, and any desired load may be coupled to the protruding free end 83 ofthe shaft 76.

As indicated by the thin-inked solid line arrows, the `air supplied from the air outlet 79 of the nas'h pump 74 passes through a check valve 84 into a heat exchanger S5. After preheated in the heat exchanger S5, the air flows through a heating chamber 86 where it is heated to an elevated temperature by means of an outside fuel burner S7. Then the energized air goes through an interaction chamber 88 where the air gives its possessing energy to the encountered water yfed from the water outlet Sil of the nash pump 74 so that the water is further pressurized. The air in the interaction chamber S is, after releasing its energy, led to the air intake 77 of the nash pump 74 through an air exhaust tube 88 and heat exchanger 85 as shown by the thin-inked solid line arrows. On the other hand, the additionally pressurized water in the interaction chamber 88 acts upon the water turbine 82 so that a rotating power may be generated on the drive shaft 76, and then it is fed back to the water intake 7S of the nash pump 74 through a cooler where the water is cooled by means of the cooling fan 8l mounted on the drive shaft 76. Although the above-described engine is formed in a closed type with respect to air, it may be easily modified to an open end type by opening the exhausttube 89 and the air intake toward an outer atmosphere. In this modification, the heating chamber 86 may be replaced by a com bustion chamber having a fuel nozzle therewithin. Examining the embodiment in FIG. 6 with regard to the energy ow, one may easily see that this mode of embodiment corresponds to that shown in FIG. lc. =It is apparent that the nash pump 74 is equivalent to the combination of the composite gas-liquid pump means 1 and the separating means 2 in FIG. lc. The separating means in this case is deemed to be of centrifugal type.

While a principle of the present invention has been described above with reference to specific apparatuses and their modifications, it should be clearly understood that all the items contained in the specification and drawings were made only by way of examples and not in a limiting sense.

The high speed screw pump referred to above is particularly used for water jet, which pump is abled to rotate at fa-r higher speed than any conventional screw pump could. This is due not only to the fact that the air is admixed but also that water flows quite naturally into the pump from the stream caused relatively by water pressure or advance of ship, instead of sucking water as seen in the conventional pumps. In order that water may readily get into the pump, water inlet is widely enough opened with a screw-thread cutting. Of course hence air is sucked into the pump by created low pressure, such Water inlet should not be opened too wide to interfere with the air inlet portion.

In this composite gas-liquid pressurizing engine, if there is a stream to counterow or pressure at the intake of the frusto-conical separator, the pump of this kind is of no need.

For example, if applied to a high speed boat, high speed water will ow countercurrently into the Water intake or if the liquid exhausted from the frusto-conical separator is returned to the intake thereof, pressure will be created by centrifugal force.

What is claimed is:

1. A composite gas-liquid engine comprising composite gas-liquid pump means for intaking gas and liquid, a liquid intake and a separate gas intake, means within the pump for combining under pressure liquid and gas passing through said intakes, said pump having an outlet for the combined gas and liquid under pressure, separation means connected to said outlet -for separating the liquid from the gas, a jet discharge device for the separated liquid, a gas turbine having a gas inlet, and means, including a gas expansion unit, for conducting the separated gas from the separation means to the gas turbine inlet.

2. A composite gas-liquid engine comprising composite gas-liquid pump means for intaking gas and liquid, a liquid intake and a separate gas intake, means within the pump for combining under pressure liquid and gas passing through said intakes, said pump having an outlet for the combined gas and liquid under pressure, separation means connected to `said outlet for separating the liquid from the gas, means, including a gas expansion unit, for conducting the separated gas from the separation means to the separated liquid to further pressurize the liquid, a hydraulic motor having a liquid inlet, and means for conducting the separated and further pressurized liquid from the separator means to said hydraulic motor inlet.

3. A composite gas-liquid engine as claimed in claim 1 in which the separation means comprises a centrifuge.

4. A composite gas-liquid engine as claimed in claim 1 in which the separation means comprises a gravity chamber.

5. A composite gas-liquid engine as claimed in claim 3 in which the centrifuge comprises a frusto-conical 70 stator and a corresponding frusto-conical rotor within the stator, inlet means at the narrower end of the stator connected to the outlet of the pump, a rst outlet means at .the Wider end of the stator adjacent the periphery for the discharge of the separated liquid and a second outlet means at said wider end adjacent the center for the discharge of separated gas.

6. A composite gas-liquid engine as claimed in claim 1 and means for controlling the ratio of gas to liquid taken in by the pump through its respective intakes.

7. A composite gas-liquid engine as claimed in claim 1 in which the gas intake includes a valve to control the ilow of air therethrough, a detector in said separation means for detecting the position of the level of separated liquid therein and means responsive to said detector for actuating said valve.

8. A composite gas-liquid engine as claimed in claim 1 in which the pump has a rotary member, said rotary member being connected to and driven by the turbine.

9. A composite gas-liquid engine as claimed in claim 1 and means for recycling exhaust gas from the turbine to the gas intake of the pump.

10. A composite `gas-liquid engine as claimed in claim 1 and means for recycling to the liquid intake of the pump, liquid discharged by the jet discharge device.

11. A composite gas-liquid engine as claimed in claim 1 in which the liquid is Water and the gas is air.

12. A composite gas-liquid engine as claimed in claim 4 in which the liquid outlet of the centrifuge is connected directly to the liquid inlet of a hydraulic motor.

13. A composite gas-liquid pressurizing engine as claimed in claim 4 in which the gravity chamber comprises a chamber having therein an upwardly extending inlet means at the lower portion of the chamber connected to the outlet of the pump, a rst outlet means at the u-pper portion of the chamber for the discharge of the separated gas, a second outlet means at the lower portion of the chamber for the discharge of the separated liquid, the upper end of said inlet means being below the lowest attainable level of the separated liquid in the chamber.

14. A composite gas-liquid pressurizing engine as claimed in claim 13 and a liquid detainer disposed immediately preceding the entrance of the iirst outlet of the separated gas.

15. A composite gas-liquid pressurizing engine as claimed in claim 1 and at least one .auxiliary pump driveably connected to the turbine to further pressurize the separated liquid.

16. A composite gas-liquid engine as claimed in claim 2 in which the pump and separator have rotary members, said rotary members being connected to yand driven by the hydraulic motor.

17. A composite gas-liquid engine as claimed in claim 1 in which the pump comprises a screw pump.

18. A composite gas-liquid engine as claimed in claim 17 in which the liquid intake of the screw pump is cut along the screw thread of the pump and the separate gas intake is adjacent to said liquid intake.

19. A composite gas-liquid engine as claimed in claim 1 in which the pump and separation means comprise a frusto-conical centrifuge having a liquid intake and a separate gas intake.

References Cited UNITED STATES PATENTS 2,033,210 3/1936 Tennant et a1. 103-148 XR 2,069,338 2/1937 Tennant 10S-148 XR 2,151,949 3/ 1939 Turner 60-108 XR 2,268,357 12/ 1941 Turner 60-49 3,137,234 6/ 1964 Mosbacher 103--2 IMARTIN P. SCHWADRON, Primary Examiner.

ROBERT R. BUNEVICI-I., Assistant Examiner. 

